<article id="wikiArticle">
<div></div>
<h2 id="Summary" name="Summary">概述</h2>
<p><strong><code>Number.parseFloat()</code></strong> 方法可以把一个字符串解析成浮点数。该方法与全局的 <a href="Reference/Global_Objects/parseFloat" title="parseFloat() 函数解析一个字符串参数并返回一个浮点数。"><code>parseFloat()</code></a> 函数相同，并且处于 ECMAScript 6 规范中（用于全局变量的模块化）。</p>
<h2 id="Syntax" name="Syntax">语法</h2>
<pre><code class="language-javascript"><code>Number.parseFloat(<var>string</var>)</code></code></pre>
<h3 id="Parameters" name="Parameters">参数</h3>
<dl>
<dt><code>string</code></dt>
<dd>被解析的字符串。</dd>
</dl>
<h3 id="返回值">返回值</h3>
<dl>
<dd>给定值被解析成浮点数，如果无法被解析成浮点数，则返回<code>NaN</code></dd>
</dl>
<h2 id="描述">描述</h2>
<p>请移步全局函数 <a href="Reference/Global_Objects/parseFloat" title="parseFloat() 函数解析一个字符串参数并返回一个浮点数。"><code>parseFloat()</code></a> 页面查看更多的解释和示例。</p>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范版本</th>
<th scope="col">规范状态</th>
<th scope="col">注解</th>
</tr>
<tr>
<td>
<p><a class="external" href="https://www.ecma-international.org/ecma-262/6.0/#sec-number.parsefloat" hreflang="en" lang="en" rel="noopener">ECMAScript 2015 (6th Edition, ECMA-262)<br/><small lang="zh-CN">Number.parseFloat</small></a></p>
</td>
<td><span class="spec-Standard">Standard</span></td>
<td>首次定义</td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility" name="Browser_compatibility">浏览器兼容性</h2>
<div><div class="blockIndicator warning"><strong><a class="external" href="https://github.com/mdn/browser-compat-data" rel="noopener">We're converting our compatibility data into a machine-readable JSON format</a></strong>.
            This compatibility table still uses the old format,
            because we haven't yet converted the data it contains.
            <strong><a class="new" href="/zh-CN/docs/MDN/Contribute/Structures/Compatibility_tables" rel="nofollow">Find out how you can help!</a></strong></div>
<div class="htab">
<a id="AutoCompatibilityTable" name="AutoCompatibilityTable"></a>
<ul>
<li class="selected"><a>Desktop</a></li>
<li><a>Mobile</a></li>
</ul>
</div></div>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
</tr>
<tr>
<td>Basic support</td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><a href="/en-US/Firefox/Releases/25" title="Released on 2013-10-29.">25</a> (25)</td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #888;" title="Please update this with the earliest version of support.">(Yes)</span></td>
<td><span style="color: #f00;">未实现</span></td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Chrome for Android</th>
<th>Firefox Mobile (Gecko)</th>
<th>IE Mobile</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
</tr>
<tr>
<td>Basic support</td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #f00;">未实现</span></td>
<td>25.0 (25)</td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #f00;">未实现</span></td>
<td><span style="color: #f00;">未实现</span></td>
</tr>
</tbody>
</table>
</div>
<h2 id="See_also" name="See_also">相关链接</h2>
<ul>
<li><a href="Reference/Global_Objects/Number" title="JavaScript 的 Number 对象是经过封装的能让你处理数字值的对象。Number 对象由 Number() 构造器创建。"><code>Number</code></a></li>
<li><a href="Reference/Global_Objects/parseFloat" title="parseFloat() 函数解析一个字符串参数并返回一个浮点数。"><code>parseFloat()</code></a></li>
</ul>
</article>